#include <stdio.h>
#include <stdlib.h>

typedef struct {
    char * name;
    int growth;
} person_t;

int name_cmp(const void * a, const void * b) {
    return strcmp(((person_t*)a)->name, ((person_t*)b)->name);
}

#define PERSONS 3

int main(void) {
    person_t array[PERSONS] = {
        { "Petrov", 178 },
        { "Sidorov", 175 },
        { "Ivanov", 180 }
    };
    int i;
    
    printf("Unsorted:\n");
    for ( i = 0; i < PERSONS; ++i )
        printf("%s\t%d\n", array[i].name, array[i].growth);
    qsort(array, PERSONS, sizeof(person_t), name_cmp);
    printf("Sorted by name:\n");
    for ( i = 0; i < PERSONS; ++i )
        printf("%s\t%d\n", array[i].name, array[i].growth);
    
    return 0;
}

Unsorted:
Petrov	178
Sidorov	175
Ivanov	180
Sorted by name:
Ivanov	180
Petrov	178
Sidorov	175